Globespan Virata Corporation

Pairgain Technologies, Inc.

Benedict A Itri

Brian Horng

John M Ross

Devin K Ng

James J Zhao

An analog front end system comprising a digital-to-analog converter, a line driver, a multiple-input device, and an analog-to-digital converter is presented. Furthermore, a method for DSL line testing comprising the steps of providing test stimuli to and receiving responses from a DSL line using an analog front end is presented. The presented system and method provides for the testing of a DSL line in an xDSL communications system deployment.

DSL line tester

A system and method for a filter tuner is presented. The system comprises a sequential logic, a register, a comparator, a first and second counter, a synchronizing logic, a first and second oscillator, a control logic, and a first and second combinational logic. The method comprises the steps of executing a calibration cycle of a filter tuner, executing a measurement cycle of the filter tuner, and tuning a filter with the filter tuner dependent on a determined cutoff frequency variation.

Filter tuner system and method

A coordinated timing technique is disclosed which allows a single analog-to-digital converter (ADC) to be timeshared by multiple digital transceivers operating on independent subscriber loops with independent sampling phase requirements. The multiple transceivers must all operate from a single master reference clock. However, any arbitrary timing phase relationship between the transceivers can be accommodated.

Timing recovery system for digital subscriber line transceivers

A frequency synthesizer for producing an output whose phase and/or frequency can be finely adjusted under digital control. The synthesizer utilizes a phase lock loop including a phase detector responsive to a prescale divide-by-N frequency divider and a feedback divide-by-M frequency divider to product an output signal F.sub.OUT. The phase of F.sub.OUT can be shifted by a small increment by slightly adjusting the values of the divisors M and N.

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Huntington Beach, CA, United States of America

Benedict A Itri